This implementation is loosely inspired by the original paper on the
Mersenne Twister, and borrows code from a public-domain implementation of
it, adapting it to fit the style of Telodendria's code, and fixing a few
bugs regarding the size of the data type used.
Neither C nor POSIX provide a good, thread-safe pseudorandom number
generator. The OpenBSD linker started complaining about the use of
rand_r(), and no standard alternative presented itself as worthy of
consideration, so I finally decided it was time to roll my own PRNG.